Lid for a beverage can or similar

ABSTRACT

The invention relates to a lid for a beverage can or similar, having a lid surface and a closure unit which is to be opened and is re-closable, which is disposed in the region of the lid surface. The closure unit has the property of selectively uncovering or closing a drinking opening in the lid surface. On the outer side of the lid a foil which, on the outer side of the lid, covers the closure unit and, around the closure unit, is entirely connected to the lid surface so as to be tight in such a manner that, on account of the connection between the foil and the lid surface, ingress of moisture is prevented or at least substantially prevented, is disposed.

The invention relates to a lid for a beverage can or similar, having alid surface and a closure unit which is to be opened and is re-closable,which is disposed in the region of the lid surface, and whichselectively uncovers or closes a drinking opening in the lid surface.

The lid, in the use state, has an inner side pointing to the inside ofthe can and an outer side pointing to the environment.

Lids of this type are known from DE 10 2010 027 821, for example. Lidsof this type for re-closable beverage cans are used, for example, forbeverage cans which are in two parts and are known per se, consisting ofa can body which is in one part and lid which is connected thereto. Thecan body here is typically shaped from aluminium or tinplate (steel),and on a longitudinal side initially includes an opening into which abeverage, for example, is filled at the bottling plant. After filling,the can body is closed by means of a lid, wherein typically the lid isconnected in a tight manner to the can body by means of a double fold.In the case of conventional beverage cans which are not re-closable, thelid in most cases is entirely composed of aluminium. A lid of this typetypically has a centrally disposed lid surface which, in the vicinity ofthe connection to the can body, is surrounded by a reinforcement bead.Typically, a drinking opening is provided in the lid surface, whichdrinking opening, in the case of conventional lids, is defined by a lidportion which can be torn open. As is known, a beverage can of this typeis opened in that a weakening line, which defines the lid portion whichcan be torn open, is torn open by means of a grip tab, and the lidportion that can be torn open is simultaneously removed or bent so as tobe out of the way. Beverage cans having lids of this type cannot bere-closed after having been initially opened.

In order to be able to re-close a beverage can after having beeninitially opened, cans having re-closable lids are known. Correspondingclosure elements are described in DE 10 2010 027 821 cited above or alsoin WO 2005/068312, for example.

The invention is based on the object of improving beverage cans of thistype.

According to the invention, this object is achieved by a lid for abeverage can or similar, having a lid surface and a closure unit whichis to be opened and is re-closable, which is disposed in the region ofthe lid surface. The closure unit has the property of selectivelyuncovering or closing a drinking opening in the lid surface. In the usestate of the lid, a side pointing to the inside of the can is the innerside of said lid, and a side pointing to the environment is the outerside of said lid. According to the invention, on the outer side of thelid a foil which, on the outer side of the lid, covers the closure unitand, around the closure unit, is entirely connected to the lid surfaceso as to be tight in such a manner that, on account of the connectionbetween the foil and the lid surface, ingress of moisture is preventedor at least substantially prevented. This is relevant in order to ensurea hygienic environment in open cavities of the closure unit bysuppressing the formation of germs for as long as possible.

The foil is multi-layered and includes at least one metallic layer andone plastic layer and one adhesive or sealing layer.

In this manner, the foil prevents or at least minimizes the risk ofmoisture absorption in various hollow spaces of the closure unit andthus excludes the risk of microbiological growth. In fact, the inventionincludes the finding that re-closable lids for beverage cans are moreproblematic in this respect than conventional tear-open lids, since mostof the closure units on the outer side of the lid have a more complexgeometry than the usual tear-open lids and are thus more sensitive tomicrobiological contamination. Moreover, closure units often includeplastic component parts which are more receptive to microbiologicalcontamination that the bright or lacquer-coated metallic faces ofconventional tear-open lids.

According to a preferred embodiment, on the outer side of the lid thefoil completely covers the closure unit. According to alternativeembodiments, however, the foil may have clearances, wherein in this casethe the periphery or the peripheries of a respective clearance is/areconnected to a surface of the closure unit in a tight manner—preferablylikewise entirely. On its part, the surface of the closure unit whichlies within such a clearance in the foil is preferably completelyclosed, such that, together with the foil and the lid surface, acompletely closed surface results.

The foil and the connection of the foil to the lid surface arepreferably conceived such that the foil is irreversibly deformed duringremoval. This permits the additional functionality of proof of beinggenuine.

Since the foil completely covers the closure unit on the outer side ofthe latter, the foil has to be initially removed in order to be able toopen a respective beverage can. By providing that the foil isirreversibly deformed in the process, the deformed foil, in the mannerof a seal, may serve as proof and indication of the respective beveragecan having been closed at origin. According to a variant of anembodiment, the foil and the connection of the foil to the lid surfaceare conceived such that the connection to the lid surface is so strongthat the foil is stretched and thus irreversibly deformed duringremoval.

According to the invention, the foil is multi-layered and preferablyincludes at least one metallic layer, such that the foil not only makesfor a liquid-tight closure but also for a gas-tight closure. The foilhere includes at least three layers, namely one metallic layer, oneplastic layer, and one adhesive or sealing layer. The latter serves forconnecting the foil to the lid surface.

Alternatively, the foil may also be breathable, in that said foil iscomposed of a plastic which contains breathable polymers, for example.

In light of the fact that at least some component parts of the closureunit typically reach outwards beyond the lid surface, it is preferablefor the foil to be pre-shaped in such a manner that said foil is adaptedto a contour of component parts of the closure unit which reach outwardbeyond the lid surface. The foil is thus preferably pre-fashioned insuch a manner that said foil follows the contour of the closure unit.This implies that the portions of the foil which are intended forconnection to the lid surface already run at least approximately in theplane of the lid surface, when a foil of this type is applied to thelid. That is to say that the application of the foil to the lid does notcoincide with comparatively large deformations of the foil, such that inthis manner a reliable and tight connection between the foil and the lidsurface can be more easily ensured.

In the case of usual lids, the lid surface is part of a shell which,besides the lid surface, also includes at least one reinforcement beadwhich entirely encloses the lid surface and which, in a surfaceinclination, transitions into the lid surface. In lids of this type itis preferable for the foil to be connected to the shell not only in theregion of the lid surface but also beyond a circumferential periphery ofthe lid surface. This is particularly advantageous where a drinkingopening which is to be closed by the closure unit is disposed close tothe periphery of the lid surface and thus also comparatively near thereinforcement bead. In this case, the face of the lid surface which isavailable between the closure unit and the circumferential periphery ofthe lid surface is so narrow that it is advantageous for the foil toreach beyond this circumferential periphery and to also be fixedlyconnected to the surface inclination which is adjacent to thecircumferential periphery. In this manner, a more secure and tighterconnection between the foil and the shell of the lid can bemanufactured. The shell of the lid is typically formed by an integralmetal plate which is correspondingly shaped.

According to the invention, a method for manufacturing a lid of the typemention above is also proposed, according to which method the foil isapplied to the remainder of the lid by means of a flexible, for examplean elastic, pressing stamp, wherein the pressing stamp is configuredsuch that it adapts to the contour of the closure unit duringapplication of the foil. It can be ensured in this manner that the foilduring application to the remainder of the lid, securely and entirelybears on the lid, more specifically on the shell of said lid. This isparticularly significant because the region between the closure unit andthe circumferential periphery of the lid surface is typically verysmall.

According to a preferred variant of the method, the foil, afterapplication, is thermally treated. In this manner, it can be ensured, inparticular, in the case of a foil which is substantially formed by athermoplastic material that the shape of the foil after applicationaccurately adapts to the surface contour of the lid, including theclosure unit. The thermal treatment of the foil may take place by way ofvarious media and, for example, may be conjoint with mechanical pressingby means of an elastic stamp, for example. However, the thermaltreatment of the foil may also take place in a non-contacting manner.

The invention is now to be explained in more detail by means of anexemplary embodiment with reference to the figures. In the figures:

FIG. 1 a shows a cross section through a lid according to the invention,including the closure unit and the foil; and

FIG. 1 b shows a lid, similar to that in FIG. 1 a, having an alternativefoil.

In FIGS. 1 a and 1 b, in each case one lid 10 or 10′, respectively,which, in the manner of known lids, includes a shell which is shapedfrom an integral metal plate and which forms a lid surface 12, areinforcement bead 14, and a core-wall inclination 16, is illustrated.The lid surface 12 here is entirely enclosed by the reinforcement bead14. In the plan view, the shape of the reinforcement bead 14 istypically circular. The reinforcement bead 14, in a surface inclination18, transitions into the lid surface 12.

The lid surface 12 includes a through-opening which, in the case ofre-closable lids, is closed by a closure unit 20 which typicallyincludes a closure element 22 lying on the inside and an actuationelement 24 lying on the outside. Since the closure element 22 isdisposed on the inner side of the lid 10 or 10′, respectively, in thecase of carbonated beverages said closure element 22, on account of aninternal pressure prevailing in a beverage can, is pressed from theinside against the shell of the lid 10 or 10′, respectively, such that asecure closure is also ensured in the case of beverage cans havinginternal pressure. The closure element 22 lying on the inside istypically connected to the actuation element 24 lying on the outside byway of a variously designed drive, such that, by means of the actuationelement 24 lying on the outside, said closure element 22 can be movedinto a position in which the closure element 22 uncovers the opening inthe lid surface 12. Details of the design of closure units of this typeare known from the prior art.

According to the invention, on the outer side of the lid 10 or 10′,respectively, a foil 30 or 30′, respectively, which completely coversthe component parts of the closure unit 20 which lie on the outside, andthe outer periphery of which is connected to the lid surface 12 andoptionally also to the surface inclination 16 in a fixed manner but,when used, in a releasable manner, is provided. This connection may beestablished by way of an adhesive layer of the foil 30 or 30′,respectively, or else also by way of a sealing layer which is connectedto the lid surface 12 and optionally the surface inclination 18 underthe effect of heat, for example.

In the case of the exemplary embodiment in FIG. 1 a, the foil 30 isformed by a preferably thermoplastic layer and, moreover, also includesa sealing or adhesive layer.

In the case of the exemplary embodiment in FIG. 1 b, the foil 30′ is ofmulti-layered construction and includes an outer plastic layer and ametallic layer lying therebeneath. The metallic layer makes for good gastightness of the foil 30′. In turn, the metallic foil, on its inner side(that is to say the side facing the lid surface), may be laminated witha further plastic layer, or also be directly provided with an adhesiveor sealing layer. In particular, a foil 30′ according the variantdepicted in FIG. 1 b has the property of irreversibly deforming duringremoval and, having been removed once, of thus not being able to bere-applied to the lid 10′ in its original state. In this case, apristine foil 30′ indicates to a consumer that the respective can hasindeed never been opened but has been closed at origin.

LIST OF REFERENCE SIGNS

-   10, 10′ Lid-   12 Lid surface-   14 Reinforcement bead-   16 Core-wall inclination-   18 Surface inclination-   20 Closure unit-   22 Closure element-   24 Actuation element-   30, 30′ Foil

1. A lid for a beverage can or similar, having a lid surface and aclosure unit which is to be opened and is re-closable, which is disposedin the region of the lid surface, and which selectively uncovers orcloses a drinking opening in the lid surface, wherein the lid, in theuse state, has an inner side pointing to the inside of the can and anouter side pointing to the environment, characterized in that on theouter side of the lid a foil which, on the outer side of the lid,completely covers the closure unit and, around the closure unit, isentirely connected to the lid surface by means of an adhesive or sealinglayer so as to be tight in such a manner that, on account of theconnection between the foil and the lid surface, ingress of moisture isprevented or at least substantially prevented, is disposed, wherein thefoil is multi-layered and includes at least one metallic layer and oneplastic layer and the adhesive or sealing layer.
 2. The lid according toclaim 1, wherein the foil and the connection of the foil to the lidsurface are conceived such that the foil is irreversibly deformed duringremoval.
 3. The lid according to claim 1, wherein the foil isbreathable.
 4. The lid according to claim 1, wherein the foil ispre-shaped in such a manner that said foil is adapted to a contour ofcomponent parts of the closure unit which reach outwards beyond the lidsurface.
 5. The lid according to claim 4, wherein the foil ispre-fashioned in such a manner that said foil follows the contour of theclosure unit in such a manner that the portions of the foil which areintended for connection to the lid surface already run at leastapproximately in the plane of the lid surface, when a foil of this typeis applied to the lid.
 6. The lid according to claim 1, in which the lidsurface is part of a shell which, besides the lid surface, includes areinforcement bead which encircles the lid surface and which, in asurface inclination, transitions into the lid surface, characterized inthat the foil is connected to the shell beyond a circumferentialperiphery of the lid surface.
 7. The lid according to claim 1, whereinthe foil completely covers the closure unit on the outer side of thelid.
 8. Method for manufacturing a lid according to claim 1, wherein onthe outer side of the lid a foil which, on the outer side of the lid,completely covers the closure unit and, around the closure unit, isentirely connected to the lid surface by means of an adhesive or sealinglayer so as to be tight in such a manner that, on account of theconnection between the foil and the lid surface, ingress of moisture isprevented or at least substantially prevented, is applied, wherein thefoil is applied to the remainder of the lid by means of a flexible, forexample an elastic, pressing stamp, wherein the pressing stamp isconfigured such that it adapts to the contour of the closure unit duringapplication of the foil.
 9. The method according to claim 8, wherein thefoil, after application, is thermally treated.